Today's Subscriber identity registration in Internet Protocol (“IP”) Multimedia System (“IMS”) using Voice over the Long-Term Evolution (“LTE”, or “VoLTE”) network (e.g., a 4G network) uses at least one mandatory step. For example, it is mandatory (excluding emergency call options) for every subscriber to authenticate with their subscription provider (Home Subscriber Server, or “HSS”) to obtain telco communication services including voice, short message service (“SMS”) (e.g., text messages), and enriched calling services as provided by their plan. Registration to an IMS network uses a subscriber identity that is typically identified by a unique IP Multimedia Private Identity (“IMPI”) and IP Multimedia Public Identity (“IMPU”). The IMPI/IMPU pair is used to uniquely identify a subscriber wherever they are in the world and route their registration back to their Home IMS domain for authentication and access upon successful registration. For solutions requiring subscribers with multiple identities (in other words a set of IMPI/IMPU pairs for a particular user), it is still required that each identity (e.g., pair identifier) is registered in the IMS network. Otherwise, the infrastructure would not know how to route calls or provide other services, for example.